There are numerous systems, such as lighting systems, which can be controlled by multiple users. In a conventional lighting system, for example, there might be a single controller which any user is free to operate in order to control the lighting system. For instance, a user may operate the controller to set a desired dim level for one or more light sources in the lighting system.
United States Patent Application US 2003/0227439 A1 proposes a method of controlling a home lighting system based on stored ‘preferences’ of users associated with the system, e.g. preferred dim levels, preferred lighting colors and/or preferred illumination patterns. The method involves receiving and processing image data captured by cameras mounted in the home, and identifying the users in the image data. The system is configured to respond to identifying one of the users by automatically implementing one or more preferences of the identified user. The patent application proposes to use preconfigured priority rules to determine how the system should respond when it is not clear which user preferences to apply, e.g. when it identifies two or more of the users in the same location at the same time. For instance, a parent's preferences may be used to configure the lighting system, rather than his or her child's preferences.
Future lighting systems may be controllable via users' personal handheld computing devices, e.g. via their smartphones, for automatically applying predefined user preferences and/or for granting manual control to the users. This may be problematic in a public lighting system, for example, since several users may make conflicting attempts to control the lighting system via their smartphones. It is likely that using preconfigured priority rules would be an inconvenient solution to this problem in some public lighting systems, due to a potential need for ongoing manual reconfiguration of the priority rules to reflect changing priorities. In lighting systems that could have very many users, for instance in a busy café or student common room, a solution based on preconfigured priority rules may be impracticable.
The issue is not limited to public lighting systems, but in principle could be relevant to almost any shared-access system. There are significant technical challenges involved in determining which user should be able to control such a system, and under which circumstances.